WACO, Texas — Baylor quarterback Bryce Petty, who sat out the second half of a 45-0 victory against SMU on Sunday night for precautionary reasons, said afterward he wasn't seriously injured and expects to play in the Bears' next game.

Petty said he took a facemask to the lower back at the end of a 16-yard run on the Bears' first series.

"I knew it right then," he said. "It just kind of locked up on me."

Petty said he could have played if necessary. Against SMU, it wasn't. The Bears led 31-0 at halftime and cruised home, recording their first shutout against an FBS opponent since 1995.

An MRI on Monday revealed that Petty has two cracked transverse processes — winglike protrusions from the vertebra. No treatment is required; managing the pain will be the issue.

The senior quarterback, who is being touted as a Heisman Trophy contender by coach Art Briles — he finished seventh in the voting in 2013 — completed 13 of 23 passes for 161 yards and two touchdowns. The normally accurate passer overthrew several open receivers and said he experienced pain every time he tried to throw.

"I couldn't really plant and throw well enough," Petty said. "It was messing with me the whole first half. It just got to the point where it was hard to stand up, so I think it was a good decision not to go back out in the second half."

After a 5-yard touchdown run early in the second quarter, Petty was slow getting up and walked gingerly off the field.

Petty said he expects to play Saturday, when the Bears host Northwestern (La.) State.

"It's nothing that serious," he said. "Everything is good."

But he walked gingerly after postgame interviews, and Briles said he wasn't sure of the prognosis for Petty.

Baylor quarterback Bryce Petty writhes in pain after a touchdown run Sunday night in Waco, Texas. This play was one of two that left Petty with lower back pain.(Photo: Jerome Miron, USA TODAY Sports)

"We're gonna have to wait and see," Briles said, adding that coaches knew something wasn't right with Petty when he missed badly on several passes to open receivers.

"That's not Bryce at all," Briles said. "Come to find out, every time he was throwing he had a sharp pain that was working on him."

Along with Petty, senior receiver Antwan Goodley did not play after the first quarter. Briles said Goodley, a preseason All-America choice by USA TODAY Sports, aggravated a strained quadriceps muscle, originally injured during practice. Briles said he wasn't sure of Goodley's status, either.

Petty started all 13 games last season, setting 17 school records while leading Baylor to 11 wins, the Big 12 championship and a Fiesta Bowl berth.

West Virginia Mountaineers wide receiver Jordan Thompson makes a catch against Alabama Crimson Tide defensive back Bradley Sylve during the third quarter of the 2014 Chick-fil-a kickoff game at Georgia Dome. (Photo: John David Mercer, USA TODAY Sports)

Texas A&M Aggies head coach Kevin Sumlin talks with his players in the huddle during a review during the first quarter against the South Carolina Gamecocks at Williams-Brice Stadium. (Photo: Jeremy Brevard, USA TODAY Sports)